M8013 Mitsubishi Plc May 2026

If you have ever opened Mitsubishi’s GX Works2 or GX Developer software to program an FX series PLC, you have likely stumbled upon a mysterious internal relay: M8013 .

----[ M8013 ]--------------( M100 ) // Heartbeat bit On the HMI, animate an invisible shape or text color based on M100. If the blinking stops, the operator knows the PLC is in STOP mode or has faulted. Mechanical pushbuttons and limit switches bounce for 5–20ms. A common trick: sample the input every 500ms using M8013. m8013 mitsubishi plc

It is neither. The "M" stands for . It exists only inside the PLC’s memory. You cannot wire a physical switch to it, and it cannot drive a real load directly. You must use its contact to trigger an output coil (Y0, Y1, etc.). M8013 vs. Other Special Relays | Relay | Pulse Rate | Common Use | | :--- | :--- | :--- | | M8011 | 10ms (100 Hz) | High-speed flashing, test pulses | | M8012 | 100ms (10 Hz) | Fast blinking, short delays | | M8013 | 1 second (0.5 Hz) | Human-scale timing, indicators | | M8014 | 1 minute (0.0167 Hz) | Long-interval polling, hour meters | Final Verdict: Should You Use M8013? Absolutely. M8013 is one of those elegant, simple tools that makes PLC programming faster and more readable. Instead of writing a 5-rung timer oscillator, you write one contact. If you have ever opened Mitsubishi’s GX Works2

----[ M8013 ]----[PLS M10]----[MOV D100 D200] // Log every second Do not use M8013 for critical timing or safety functions. The "M" stands for

----[ M8013 ]----[ X0 ]-----( M0 ) // Latched, debounced input This ensures you only register one "press" per second, ignoring chatter. Want to record temperature or pressure once per second? Use the rising edge of M8013 ( M8013 from OFF→ON) to trigger a MOV or WRITE instruction.

At first glance, it looks like just another auxiliary relay. But in the world of industrial automation, M8013 holds a special place. It is often the first clock pulse a trainee learns, and the last debug tool an experienced engineer reaches for.